1. Technical Field
The present invention relates to a method for making an improved rolled snack food and more particularly to a method for making a rolled snack food having a light and crispy texture.
2. Description of Related Art
Conventional tortilla snack piece products are prepared from corn masa dough made from a traditional nixtamalization process. The masa dough is then compressed between a pair of counter rotating sheeter/cutter rollers that are located closely together, thereby providing a pinch point through which the dough is formed into sheets and cut into a desired shape. Often the desired snack piece shape is that of a triangle. After the dough is cut, the snack pieces are transported towards and through a toaster oven for an increased stiffness for insertion into the fryer. The toasted snack pieces are then passed through a proofing stage where the snack pieces are exposed to ambient air to equilibrate moisture throughout the snack piece. The snack pieces are then fried in hot oil before being routed into a seasoning tumbler where flavored seasonings or salts are added to the snack pieces. The snack pieces are then sent to be packaged.
Snack pieces made from this process typically have a substantially flat geometry, even if the snack pieces have a curl as a result of the frying process. However, there are advantages for snack pieces to have to other geometries. For example, a rolled snack piece can be more easily placed into a consumer's mouth, resulting in a bite-sized or more easily consumable snack. Moreover, the bulk density of rolled snacks is higher than the bulk density of snacks having a substantially flat geometry. As a result, less packaging can be used to contain the same weight of rolled snacks. Accordingly, a need exists for a rolled snack food.
A rolled snack food can be made by rolling the cut dough pieces following sheeting before the pieces are toasted. One such apparatus for rolling pieces of dough is disclosed is U.S. Pat. No. 6,393,974. Unfortunately, texture problems that do not occur in prior art flat snack pieces arise during cooking of rolled dough pieces. For example, when prior art substantially flat snack pieces are cooked in hot oil, steam within the dough can cause the snack pieces to expand mostly outward. This outward expansion creates voids within the snack piece. These voids help create a lighter, crispier texture.
In a rolled snack piece, however, the expansion occurs radially, both inward and outward. When the rolled snack piece is placed into the fryer, the moisture in contact with the hot oil in the outer portion of the fried snack piece turns to steam causing both inward and outward radial expansion of the snack piece. The inward expansion of the rolled snack food, upon insertion into the fryer, closes off the inner portion of the rolled snack food. Thus, frying oil does not fully permeate the rolled snack piece. This inhibits oil displacement of water. Corn masa becomes hard and unpalatable at low oil levels. As a result, the inner portion of the snack piece has an undesirably hard texture. Moreover, inward radial expansion further compresses the inner portion of the snack piece which increases the particulate density, and decreases any voids that help provide a lighter, crispier texture. A higher particulate density means there are fewer voids to provide a lighter, crispier texture. As a result, a hard texture is created throughout the inner portion of the rolled snack food. Hence, a need exists for a method to control inward expansion of a rolled snack food during frying.
In addition, while the moisture content upon leaving the toast oven in a prior art substantially flat masa-based snack piece is between about 25% and about 35% moisture, the moisture content of a rolled dough snack piece, upon leaving the toast oven, is about 45% to 50% moisture. There is a larger temperature gradient within a rolled snack piece that makes it more difficult to remove water uniformly. This is due, in part, to the decreased surface area that the rolled dough has exposed in the toast oven. For example, as the rolled snack piece passes through the toast oven, the temperature of the inner part of a rolled snack piece is lower than the temperature of the outer, exposed part. This results in uneven moisture removal, and higher moisture contents near the inner portion of the rolled snack piece. As indicated above, because the inner portion of the snack piece is closed off during frying, it is difficult to remove the moisture by oil displacement in the inner portion of the snack piece. Higher moisture contents in the finished snack piece product can contribute to a harder texture.
Consequently, the need exists for a rolled snack piece having a light, crispy texture. Moreover, a need exists for the light, crispy texture to be substantially uniform throughout the cross-section of the rolled snack piece.
Several prior art solutions were tried in an attempt to satisfy this need. For example, one prior art solution for softening a fried dough involves using a potato or rice starch. When these starches are heated and fried at high moisture contents, the starch binds tightly to itself resulting in a glassy, hard texture. This glassy texture typically allows for rapid breakdown of the snack during mastication. Unfortunately, when potato or rice starch was added to the masa used in the rolled snack piece, the rolled snack pieces expanded radially inward, forcing the rolled snack piece to close up upon frying, and made the product bind so tightly that breakdown failed to occur during mastication. Thus, adding potato or rice starch, rather than resulting in a softer texture, resulted in a highly undesirably hard texture.
Other prior art softening compounds such as dextrins and lecithins failed to survive the frying process and resulted in excessive browning of the rolled snack pieces. Moreover, strong off flavors also became apparent. Fully hydrogenated, high melting vegetable oil (less than 5 iodine value) was also tried. Such oil provides voids in the food products creating less hardness, however, the hardstock leached directly into the oil due to its inability to complex with the starch in the masa. Moreover, oil quality was negatively impacted. Hence, a need exists for a method of making a fried, rolled snack piece having a light, crispy texture. The method should be conducive to cooking in hot oil, yet not severely impact oil quality. Moreover, the method should avoid excessive browning and off-flavors.